From a81fc41c3eb99e8fc52aa734ee63e13c937aab81 Mon Sep 17 00:00:00 2001 From: JanHenrik Date: Sun, 19 Jan 2020 00:56:37 +0100 Subject: added blink example --- .../DSP/Source/FastMathFunctions/arm_cos_q31.c | 84 ++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 Blink/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_cos_q31.c (limited to 'Blink/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_cos_q31.c') diff --git a/Blink/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_cos_q31.c b/Blink/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_cos_q31.c new file mode 100644 index 0000000..105addb --- /dev/null +++ b/Blink/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_cos_q31.c @@ -0,0 +1,84 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_cos_q31.c + * Description: Fast cosine calculation for Q31 values + * + * $Date: 27. January 2017 + * $Revision: V.1.5.1 + * + * Target Processor: Cortex-M cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "arm_math.h" +#include "arm_common_tables.h" + +/** + * @ingroup groupFastMath + */ + + /** + * @addtogroup cos + * @{ + */ + +/** + * @brief Fast approximation to the trigonometric cosine function for Q31 data. + * @param[in] x Scaled input value in radians. + * @return cos(x). + * + * The Q31 input value is in the range [0 +0.9999] and is mapped to a radian + * value in the range [0 2*pi). + */ + +q31_t arm_cos_q31( + q31_t x) +{ + q31_t cosVal; /* Temporary variables for input, output */ + int32_t index; /* Index variables */ + q31_t a, b; /* Four nearest output values */ + q31_t fract; /* Temporary values for fractional values */ + + /* add 0.25 (pi/2) to read sine table */ + x = (uint32_t)x + 0x20000000; + if (x < 0) + { /* convert negative numbers to corresponding positive ones */ + x = (uint32_t)x + 0x80000000; + } + + /* Calculate the nearest index */ + index = (uint32_t)x >> FAST_MATH_Q31_SHIFT; + + /* Calculation of fractional value */ + fract = (x - (index << FAST_MATH_Q31_SHIFT)) << 9; + + /* Read two nearest values of input value from the sin table */ + a = sinTable_q31[index]; + b = sinTable_q31[index+1]; + + /* Linear interpolation process */ + cosVal = (q63_t)(0x80000000-fract)*a >> 32; + cosVal = (q31_t)((((q63_t)cosVal << 32) + ((q63_t)fract*b)) >> 32); + + return cosVal << 1; +} + +/** + * @} end of cos group + */ -- cgit